1. Field of the Invention
The present invention relates to a bridge for heterogeneous QoS networks, and more particularly, to a bridge for heterogeneous QoS networks, which can provide QoS required by all application services using a universal plug and play (UPnP) QoS structure.
2. Description of the Related Art
As a home network technology has been advanced, a demand of multimedia services for transmitting/receiving not only simple text but also audio/video data has increased abruptly. In order to provide the multimedia service, it requires sufficient bandwidth in a home network and a method for providing various service requirements for multimedia service in a network.
A universal plug and play (UPnP) is a representative home network middleware for providing various audio/video (NV) services. The UPnP is driven based on IP networking, and the structure thereof is defined using widely used protocols in the Internet such as a transmission control protocol (TCP), a user datagram protocol (UDP), a hyper text transfer protocol (HTTP), and an extensible markup language (XML). The object of UPnP is to provide a seamless network between devices using various mediums in a home network, and not require a user's or a manager's efforts when a device is added or removed to/from a network. Particularly, UPnP QoS structure provides a method for exchanging connection information and graphic characteristics of a service so as to provide QoS of application service to devices controlled through the UPnP.
Furthermore, various network technologies have been introduced for providing multimedia service in a home network. Homeplug AV (HPAV) using a high speed power line and WiNET using wireless signal are representative technologies among them.
The HPAV is the next generation standard technology of HomePlug Power line Alliance, which provides high quality, multistream and home entertainment environment through a power line in a house. The HPAV employs an enhanced physical layer technology and a MAC layer technology for providing 200 Mbps level power line network. Particularly, the MAC layer provides a Carrier Sense Multiple Access (CSMA) and a Time Division Multiple Access (TDMA) that guarantees bandwidth reservation, high reliability, strict control of delay time and jitter.
On the contrary, the WiNET is a sub layer of a WiMedia network protocol, and is a protocol adaptation layer (PAL) of a WiMedia wireless platform to be operated as Ethernet or IEEE 802.3. The WiNET allows a home network to be transformed to a wireless personal area network (WPAN) without modifying a typical TCP/IP application program. The WiNET provides a link layer service for an upper layer protocol such as IPv4 or IPv6, and uses services provided from a WiMedia wireless platform for transmitting and receiving PDU. Supplementary, the WiNET provides an asynchronous broadcast transmission scheme and a multicast PDU for saving power consumption of a device operated based on battery power, and guarantees QoS using TSPEC using UPnP or RSVP. The WiMedia wireless platform is a WPAN structure that includes WiMedia PHY/MAC, WiMedia Multiplexing (WiMUX), and WiMedia MAC Convergence Architecture (WiMCA).
FIG. 1 is a block diagram illustrating a general structure of a home network bridge connecting a wireless network and a wired network such as HPAV and WiNET according to the related art.
As shown in FIG. 1, the conventional bridge apparatus for a typical home network includes a bridge function unit 31 for performing a bridge function to data communication between a first network and a second network, a first network device driver 32 connected to the first network for performing operations to communicate through the first network, and a second network device driver 33 connected to the second network for performing operations to communicate through the second network. The bridge function unit 31 receives data frames through the first and second network device drivers 32 and 33, decides a destination network based on a second layer address of a destination, transforms the received data frames to have a format suitable to the decided destination network, and instructs a corresponding network device driver 32 or 33 to transmit the transformed data frame.
In a home network, the first network may be a wired network, for example, a power line communication (PLC) network, and the second network may be networks different from the PLC network, for example, a wireless network. More particularly, the second network may be a WiNET.
In case of the bridge according to the related art, the bridge only has information about the second layer and does not have information about connection defined in the application layer and QoS information. Therefore, a transmitter is allowed to transmit all frames to destination thereof but cannot satisfy the QoS requirements required by the user.
In order to satisfy the QoS requirements, the bridge must detect the characteristics of each application service and provides the QoS according to the detected characteristics thereof.
Since the two different networks connected through the bridge provide different QoS mechanisms, the heterogeneity problem of a QoS is required to solve for guaranteeing QoS between ends stations and for stably providing QoS.